used yfz450 need help

[300ex07]

We just bought a 04 yfz 450 the other day when you got it it didnt smoke, i guess we didnt let is completley warm up when we checked it out. Because we were messing around with it when we got it home and after it gets completley hot it smokes really bad and has a tick. Does anyone have any ideas? do the valves just really need adjusted or does it need a rebuild???

Thanks

[ghott]

What color smoke?
When does the smoke happen? Full throttle...idle??

450's normally have a "tick." But if it doesn't sound normal...check for an exhaust leak. Check the valve adjustment as well.

If the smoke is black...its gas. If its white, its water. Check your coolant level. If its purple-blueish its oil. Check your oil level. How many hours are on it? Could be the piston rings are shot.

[DieselBoy]

i feel your pain. its hard to make sure it doesnt smoke when you buy them. I always ride the christ out of it when im test riding it (well, usually) to make sure it gets nice and toasty so I can see if it smokes/has any problems. It's the only way.

[Kennethyfz450]

Change your oil
New Spark Plug
New gas (sometimes 2stroke oil gets mixed in gas jugs)
then try it